Scientists cure Muscle Paralysis in Mice

Photo credit: John Carnett/Popular Science – Optogenetics, tested in rodents, can control electrical activity in a few carefully selected neurons.

Searching for a new way to cure paralysis, a team of scientist has come up with a remarkable and off the wall idea. This discovery comes out of the labs at the University College London. The team, lead by Linda Greensmith, used stem cells and optogenetics to control leg muscles in mice and completely circumvent the nervous system in the process.

For those of you who are not familiar with Optogenetics [and really, why would you be familiar with it?] here is a overly simple rundown of what we are talking about.

Optogenetics is a very new field that involves the use of light to control certain neurons that have been modified to respond to the stimuli; normally neurons are controlled by electrical signals and tell your body to move [muscles to contract] or feel pain.

With this method, genes are inserted into neurons to make them respond to the light signals [for this research they used an algal gene that codes for a light-responsive protein into mouse embryonic stem cells]. Those neurons are then placed into the mouse — the neurons are stimulated with light, which in turn causes the muscle to contract.

This method has a large advantage over using electrical signaling because the intensity can be better controlled — using electric signals, muscles contract too forcefully, with light you can increase the level of light to increase the response, “It gives a very smooth contraction,” says Greensmith. Using electricity can also be quite painful, when the nerves still have the ability to feel pain, which can be a stumbling block when dealing with paralysis .

There is still a lot of work to be done before this can be translated into humans of course, but what is next?

The group wants to help restore breathing for people with motor neuron disease. The idea is to develop a ‘cuff’ of light responsive neurons that can be wrapped around the nerve and be stimulated via a battery pack implanted under the skin.

Other applications being explored for optogenetics involve treatments for epilepsy and parkinson’s disease. It will be exciting to see just what comes next, especially when you keep in mind, this field of research is still in it’s infancy.

Stay tuned and who knows, maybe optogenetics won’t be such a foreign sounding word in the upcoming years.